This invention relates generally to improvements in digital versatile disc systems and, more particularly, to a system for selecting and defining a primary viewing angle and secondary viewing angles and synchronizing the assorted angles for display.
Digital versatile discs (DVDs) are information storage devices used for storing prerecorded audio information, movies and computer software. The storage and playback mechanism used in DVDs closely resembles the mechanism used in compact discs (CDs) and DVD players and software use the same laser technology as CD players. Briefly, both DVDs and CDs store information as a pattern of pits formed in a metallic substrate. The pit patterns form digital words and can be read by shining a laser beam on the disc surface and detecting the reflected beam. However, the information storage capacity of a typical DVD is much higher than a CD. Presently available DVDs have a variety of capacities which depend on the technology used to manufacture the discs. Single-layer technologies can be either single or double-sided with capacities of 4.7 gigabytes and 9.4 gigabytes, respectively. Dual layer technologies will soon be available which use single or double sided capacities that hold approximately 8.5 gigabytes per side. This high information storage capacity makes DVDs suitable for storing not only audio information, but also video information and large amounts of computer data as well.
DVD players have many CD player features, such as the ability to play selections in any order desired and the ability to read information from any point on the disc. However, DVDs can store information in several formats. For example, DVDs which are used to store video information, hereinafter called DVD-VIDEO discs, may use various known information compression algorithms, such as MPEG-2 for video compression/decompression. A DVD may also include high fidelity sound in the form of pulse code modulated data streams which may have varying sample rate. Still other DVD versions (hereinafter called DVD-ROM discs) can store digital data for computer use, and the data may also be compressed on these discs.
With the improved storage capability of DVD content discs, multiple versions of the same subject matter may be stored and interleaved upon the storage disc. Current DVD specifications allows each DVD title to store up to nine viewing angles of the same subject matter. These nine viewing angles may be composed of different subject matter, but when they are the same subject matter, it is advantageous to be able to display multiple views of the same subject matter at the same time. For example, a football coach may wish to see both first and third person views of a play or game in order to see how players perform as individuals and also as a team. Likewise, an instructor may desire to show a group performance and isolate several individual performances within the group in order to compare and contrast the different styles. Unfortunately, all known and currently available DVD players can only display a single angle at a time. As a result, the user(s) must play each angle individually in order to review.
Accordingly, a need exists for a DVD system and method that allows multiple viewing angles from the same content disc to be displayed on a common display. Further, a need exists for a way of selecting a primary viewing angle and then subordinating any additional viewing angles to the primary viewing angle.
According to the present invention, a method and apparatus are disclosed within a DVD player that allows multiple view angles to be displayed on a common display with one view angle designated as a primary view and the remaining view angles being subordinated to the primary view angle. The system and method also provide that any Modifications to the primary view similarly affect the secondary views. Any of the secondary views may be selected at any time to become the primary view whereupon the remaining viewing angles are subordinated and synchronized with the newly selected primary view.
The DVD apparatus is capable of retrieving multiple views from a DVD content source and displaying these views on a video display connected to the apparatus. The display apparatus includes a parser that is responsive to a data stream retrieved from the DVD content source. The parser extracts multimedia data from the source. The multimedia data includes at least a video data portion, an audio data portion and a subpicture data portion for each of the multiple views. The user selects one of the multiple views to be a primary or a first view. The user then also selects additional views anywhere from one to however many views are possible in the angle block supplied on DVD content. The video decoder is coupled to the parser and is used to display each of the multiple views based on the video data portion parsed out of the data stream. An audio decoder is coupled to the parser and it plays the audio data portion of the primary view only. A subpicture decoder is also coupled to the parser and it is used to display selected menu information for the primary view based on subpicture data portion of the primary view as it is parsed from the data stream. The video decoder displays the primary view in a first window and the successive depending views are displayed in subwindows within the video field. These windows may either be inside the primary window or outside the first window depending upon the selection of the user. In response to any user request, the system modifies the primary view during play and this modification is translated to each of the multiple views also being displayed. In order to have each view play at the same time, the parser synchronizes the primary view to a master clock and then each subsequent secondary view is synchronized to the primary view in time and playback. At any time, the user may select to change the primary view to a new view. During this change, all remaining multiple views and the current primary view becomes subordinated to the newly selected primary view. Additionally, the user may select additional secondary views to display simultaneously with the first primary view if so desired. Each time a secondary view is selected, it is synchronized to the primary view and the remaining multiple views.
The present invention further includes a method for retrieving multiple views from a DVD content source and displaying these views on a video display. The method comprises the steps as follows. Initially, in response to a data stream retrieved from the DVD content source, the parser extracts multimedia data therefrom. Next, the system displays each of the multiple views based on the video data portion corresponding to each of the multiple views. Additionally, the method provides for playing the audio portion of the primary view and for displaying selected menu information for the primary view based upon subpicture data retrieved from the data stream. The method provides that the primary view is displayed in a first window while the remaining views are displayed in secondary windows. These windows for the secondary views may be inside the primary window or outside the primary window depending upon the choice of the user. Anytime a user requests modification of the primary view, the method provides that the primary view be so modified and that each multiple view also be modified in a like manner. The method may be reduced as computer program code for implementation on a computer system capable of operating in a DVD environment. The computer code modifies the system to perform the various methods best described in a newly configured computer environment as directed by the code.